.page-about {
  --about-gap: clamp(28px, 4vw, 52px);
  --about-pad: clamp(40px, 6vw, 96px);
  padding-bottom: clamp(48px, 7vw, 96px);
  color: var(--chalk);
}

.page-about .breadcrumbs {
  padding-block: 22px 4px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(24px, 4vw, 52px) clamp(48px, 6vw, 88px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -22%;
  right: -12%;
  width: min(64vw, 720px);
  height: min(64vw, 720px);
  background: radial-gradient(circle, rgba(255, 107, 30, 0.18) 0%, rgba(255, 107, 30, 0) 64%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: -14%;
  bottom: -28%;
  width: min(48vw, 520px);
  height: min(48vw, 520px);
  background: radial-gradient(circle, rgba(62, 232, 176, 0.12) 0%, rgba(62, 232, 176, 0) 64%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  display: grid;
  gap: clamp(28px, 4vw, 44px);
  align-items: end;
}

.page-about .about-hero__title {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 18px 0 22px;
}

.page-about .about-hero__title .display {
  font-weight: 200;
  font-size: clamp(76px, 18vw, 168px);
  line-height: 0.9;
  letter-spacing: -0.035em;
  color: var(--chalk);
  margin: 0;
}

.page-about .about-hero__title-sub {
  font-size: clamp(17px, 2.6vw, 26px);
  font-weight: 500;
  line-height: 1.35;
  color: var(--chalk-muted);
  max-width: 22ch;
}

.page-about .about-hero__lede {
  font-size: 16px;
  line-height: 1.8;
  color: var(--chalk-muted);
  max-width: 62ch;
  margin: 0;
}

.page-about .about-hero__index {
  background: var(--ink-700);
  border: 1px solid var(--ink-500);
  border-radius: var(--r-md);
  padding: 22px;
}

.page-about .about-hero__index-label {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--flare);
  text-transform: uppercase;
}

.page-about .about-hero__index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-hero__index-list a {
  display: flex;
  gap: 12px;
  align-items: baseline;
  padding-left: 12px;
  border-left: 2px solid var(--ink-500);
  font-size: 14px;
  color: var(--chalk);
  text-decoration: none;
  transition: border-color 200ms var(--ease-out), color 200ms var(--ease-out);
}

.page-about .about-hero__index-list a:hover,
.page-about .about-hero__index-list a:focus-visible {
  border-left-color: var(--mint);
  color: var(--mint);
  outline: none;
}

.page-about .about-hero__index-list .numeric {
  font-size: 15px;
  color: var(--amber);
  min-width: 4.4ch;
}

/* ---------- 通用正文段 ---------- */
.page-about .about-section {
  padding-block: var(--about-pad);
}

.page-about .about-section__head {
  max-width: 68ch;
  margin-bottom: var(--about-gap);
}

.page-about .about-section__head .index-num {
  display: block;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--flare);
  margin-bottom: 10px;
}

.page-about .about-section__title {
  margin: 0;
  font-size: clamp(24px, 3.6vw, 40px);
  font-weight: 700;
  line-height: 1.16;
  color: var(--chalk);
}

.page-about .about-section__lede {
  margin: 14px 0 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--chalk-muted);
}

.page-about .about-columns {
  display: grid;
  gap: 26px;
}

.page-about .about-aside {
  border-left: 2px solid var(--mint);
  padding-left: 16px;
}

.page-about .about-aside__label {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--mint);
  text-transform: uppercase;
}

.page-about .about-aside__note {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--chalk-muted);
}

.page-about .about-aside__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--chalk-muted);
}

.page-about .about-aside__facts .numeric {
  font-size: 19px;
  color: var(--chalk);
  margin-right: 6px;
}

.page-about .about-main .prose p {
  margin: 0 0 20px;
  font-size: 16px;
  line-height: 1.82;
  color: var(--chalk-muted);
  max-width: 68ch;
}

.page-about .about-main .prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 图片 ---------- */
.page-about .media {
  margin: 34px 0 0;
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--ink-700);
  border: 1px solid var(--ink-500);
}

.page-about .media--square {
  border-radius: var(--r-lg);
}

.page-about .media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media__caption {
  padding: 14px 20px 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--chalk-muted);
  border-top: 1px solid var(--ink-500);
}

/* ---------- 时间带 ---------- */
.page-about .about-timeline {
  padding-inline: 0;
}

.page-about .about-timeline__banner {
  margin-top: 0;
}

.page-about .timeline-scroller {
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x mandatory;
  padding-block: 30px 16px;
  scrollbar-width: thin;
  scrollbar-color: var(--flare) var(--ink-500);
}

.page-about .timeline-scroller:focus-visible {
  outline: 2px solid var(--flare);
  outline-offset: -2px;
  border-radius: var(--r-sm);
}

.page-about .timeline-track {
  position: relative;
  display: flex;
  gap: 22px;
  min-width: max-content;
  margin: 0;
  padding: 0 clamp(20px, 5vw, 64px);
  list-style: none;
}

.page-about .timeline-track::before {
  content: "";
  position: absolute;
  top: 82px;
  left: clamp(20px, 5vw, 64px);
  right: clamp(20px, 5vw, 64px);
  height: 1px;
  background: linear-gradient(90deg, var(--flare), var(--mint) 52%, var(--ink-500));
  opacity: 0.55;
  pointer-events: none;
}

.page-about .timeline-node {
  position: relative;
  flex: 0 0 auto;
  width: min(276px, 74vw);
  scroll-snap-align: start;
}

.page-about .timeline-node__year {
  display: block;
  font-size: 42px;
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 1;
  color: var(--chalk);
}

.page-about .timeline-node__dot {
  display: block;
  width: 12px;
  height: 12px;
  margin: 30px 0 0;
  border-radius: 50%;
  background: var(--flare);
  box-shadow: 0 0 0 4px rgba(255, 107, 30, 0.16);
}

.page-about .timeline-node__title {
  margin: 18px 0 8px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--chalk);
}

.page-about .timeline-node__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--chalk-muted);
}

/* ---------- 架构调整列表 ---------- */
.page-about .arch-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .arch-item {
  padding: 24px 0;
  border-top: 1px solid var(--ink-500);
}

.page-about .arch-item:last-child {
  border-bottom: 1px solid var(--ink-500);
}

.page-about .arch-item__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 14px;
  margin-bottom: 10px;
}

.page-about .arch-item__stage {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .arch-item__title {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--chalk);
}

.page-about .arch-item__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--chalk-muted);
  max-width: 62ch;
}

/* ---------- 场景横带 ---------- */
.page-about .scenario-list {
  display: grid;
  gap: 0;
}

.page-about .scenario-item {
  display: grid;
  gap: 10px;
  padding: 26px 0;
  border-top: 1px solid var(--ink-500);
}

.page-about .scenario-item:last-child {
  border-bottom: 1px solid var(--ink-500);
}

.page-about .scenario-item__tag {
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--mint);
}

.page-about .scenario-item__title {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--chalk);
}

.page-about .scenario-item__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--chalk-muted);
  max-width: 66ch;
}

/* ---------- 收束 ---------- */
.page-about .about-cta {
  padding-block: clamp(56px, 8vw, 104px) 24px;
}

.page-about .about-cta__inner {
  position: relative;
  overflow: hidden;
  display: grid;
  gap: 26px;
  padding: clamp(26px, 4.6vw, 52px);
  border-radius: var(--r-lg);
  border: 1px solid var(--ink-500);
  background:
    radial-gradient(circle at 88% 12%, rgba(255, 107, 30, 0.22) 0%, rgba(255, 107, 30, 0) 58%),
    linear-gradient(150deg, var(--ink-700) 0%, var(--ink-500) 100%);
}

.page-about .about-cta__title {
  margin: 0 0 12px;
  font-size: clamp(22px, 3.2vw, 34px);
  font-weight: 700;
  line-height: 1.2;
  color: var(--chalk);
}

.page-about .about-cta__text {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--chalk-muted);
  max-width: 58ch;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-reg {
  margin: 26px 0 0;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--chalk-muted);
}

.page-about .about-reg .numeric,
.page-about .about-reg {
  font-family: var(--font-mono);
}

/* ---------- 响应式 ---------- */
@media (min-width: 860px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.7fr) minmax(240px, 0.9fr);
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .about-columns {
    grid-template-columns: 212px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 56px);
  }

  .page-about .about-aside {
    padding-left: 20px;
  }

  .page-about .scenario-item {
    grid-template-columns: 108px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 40px;
  }

  .page-about .about-cta__actions {
    flex-direction: column;
    align-items: stretch;
  }
}

@media (min-width: 1180px) {
  .page-about .timeline-track {
    gap: 30px;
  }

  .page-about .timeline-node {
    width: 300px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline-scroller {
    scroll-behavior: auto;
  }

  .page-about .about-hero__index-list a {
    transition: none;
  }
}